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QUOTE (ErikS @ Nov 29 2005, 02:04 AM)

QUOTE (ChiGung @ Nov 29 2005, 02:32 AM)

because the test corpus is expected to be more challenging, more complex.

Why?

I think you make a couple of mistakes if you do that.

Firstly, who defines complex? Is it defined by looking at how high bitrate the encoders allocate for a particular part? <snip>

I meant complex casualy as tending to encode with more bits, not for a deliberate policy 'saying for test purposes that the samples should be more complex, its just that on balance, samples choosen for human listening interests will probably tend to average out higher in bitrate than those choosen entirely randomly.Theres sure merit for choosing entirely randomly, or making sure the samples alone achieve overall the average bitrate, I could go with that, but then to be honest I dont see my listening abilities being able to perform this test myself. The decisions are up to test participants and conductors. Im interested in the result, much preferably with wma standard included. Im interested in getting people to understand the 'wma 2pass solution' which negates the previously percieved 'wma 2pass problem' So that if you want to test it you can.

JohnV said that Nero will probably use ABR for the test, that makes the unfairness of rejecting 2pass wma standard options even more stark.

And the vote is unfair, i didnt vote in it, because obviously wma standard would be too badly handicapped by using q50 (20% reduction in target bitrate) It wouldnt be handicaped or unfairly advantaged by using 2pass on the joined samples, *especialy if the samples are to target average bitrate themselves, or a larger targeting corpus is included in the encode.

But during the course of this loopy thread, wma standard has been discouraged for ultimately invalid objections to its only suitable encoding mode - thats gonna reflect poorly on the test and forums expertise for those with the insight to see the 2pass method for what it really is (an ideal automated analogue of manual bitrate targeting processes)

It wouldnt be handicaped or unfairly advantaged by using 2pass on the joined samples, *especialy if the samples are to target average bitrate themselves, or a larger targeting corpus is included in the encode.

No, but the distribution of WMA bits in each sample wouldn't be identical to a real world encoding of the same, full tracks at the same setting (128, 2-pass). Therefore the results of the test would be very hard to interpret, or even meaningless.

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QUOTE (naylor83 @ Nov 29 2005, 01:15 PM)

QUOTE (ChiGung @ Nov 29 2005, 03:11 PM)

It wouldnt be handicaped or unfairly advantaged by using 2pass on the joined samples, *especialy if the samples are to target average bitrate themselves, or a larger targeting corpus is included in the encode.

No, but the distribution of WMA bits in each sample wouldn't be identical to a real world encoding of the same, full tracks at the same setting (128, 2-pass). Therefore the results of the test would be very hard to interpret, or even meaningless.

Neros ABR wouldnt be identical either, and other vbr encodes, depending on their encoders precise implementation wouldnt be precisely the same for encoded sample only, than in-track encodes. Theres also encoding start up differences to fuss over, each vbr individual vbr encode can have 'run-in' differences and 'run-out' differences as the small sample starts and finnishes.

And as for how different the 2pass encodes would sound from their specific settings, firstly if no identifiable advantage or disadvantages can be proposed (very difficult to propose because of the relativistic* nature of the global vbr setting within the final 2pass) particular differences will balance themselves out, helping one sample while hindering another (there are many many such variances in individual performances in a test like this) Secondly the differences, should in fact be very small when the sample corpus bitrate is normalised, or the 2pass bitrate is achieved using an added larger 'targeting corpus'

Its very easy to recognise that there will be differences, you need to look deeper, compare overall processes to rate the importance of the possible differences. As soon as you examine and contrast the (normaly unerecogised) manual process of targeting a bitrate that is used in one way or another to specify or check all the codecs settings - with wma st. automated process, you will realise what these differences amount to in practice - nada

edit: *, sorry - jargon abused. I wasnt refering to Einstiens theory there, just how the bitrate distribution tends to remain relative across time with a global vbr method even as different mean bitrates are targeted

Neros ABR wouldnt be identical either, and other vbr encodes, depending on their encoders precise implementation wouldnt be precisely the same for encoded sample only, than in-track encodes. Theres also encoding start up differences to fuss over, each vbr individual vbr encode can have 'run-in' differences and 'run-out' differences as the small sample starts and finnishes.

Didn't think about that.

QUOTE (ChiGung @ Nov 29 2005, 03:36 PM)

And as for how different the 2pass encodes would sound from their specific settings, firstly if no identifiable advantage or disadvantages can be proposed (very difficult to propose because of the relativistic nature of the global vbr setting within the final 2pass) particular differences will balance themselves out, helping one sample while hindering another (there are many many such variances in individual performances in a test like this) Secondly the differences, should in fact be very small when the sample corpus bitrate is normalised, or the 2pass bitrate is achieved using an added larger 'targeting corpus'

Its very easy to recognise that there will be differences, you need to look deeper, compare overall processes to rate the importance of the possible differences. As soon as you examine and contrast the (normaly unerecogised) manual process of targeting a bitrate that is used in one way or another to specify or check all the codecs settings - with wma st. automated process, you will realise what these differences amount to in practice - *nada

Ok. Can't quite get my mind around that, at least not right now. I'll just take your word for it.

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QUOTE (naylor83 @ Nov 29 2005, 01:42 PM)

Now - will Sebastian also take your word for it?

If they cant visualise what Im saying (the equivalence with manual multipass targeting method that goes on explicitly or in kind) I wouldnt suggest anyone takes my word for it - a concensus from Codec Dev's would be persuasive.

Well, looks like WMA Professional is gonna win the poll for the 5th contender. Good thing for Microsoft and WMA when the test results are out, since most people outside HA probably don't realize there's actually a significant difference between these codecs. The other one, higher quality - almost nowhere used, other one lower quality and used very widely. Interesting to see the results though.

On a sidenote: Is there a command line encoding utility for WMA Pro? I'd like to try that beast out.

The fifth competitor poll can be closed now - the winner is WMA Professional Q50 9.1 which received a total of 60 votes out of 122 (49.18%).MusePack came second with 25 votes, followed by None with 23 votes and WMA Standard Q50 with 14 votes.

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QUOTE (ff123 @ Nov 29 2005, 03:20 PM)

run-in differences are mitigated by setting abchr-java to start playing 1 second into the sample.If nero's abr is like lame's abr, it doesn't work the same way as wma vbr 2-pass. That is, it would be a 1-pass abr, so there wouldn't be the same problem with encoding just short samples.

Neros 1pass ABR will have relatively massive run-in discrepancies with the samples encoded insitu. If wmas 2pass targeting is unnacceptable Neros ABR is definitely out of the question.

QUOTE (Alex B)

Congrats for the winner!

And now back to the samples...

The vote was really flawed -you all know it.

Now my last attempt at waving the truth in front you guys:Suppose 3 phrases joined: A, B and C

It would be wonky for the prepass calculated vbr setting not to be global, assuming it is, this equation would be true:

That equation illustrates (by being linear) that the bitrate demands of A and B (Phrase_Demandrate*phraseDuration) remain in proportion with each other, nomatter what the demand of C. To be fair C's demand only needs to be normalised because if it is greater than (A+B)/2, A+B is deprived, if it is less A+B is boosted.C can be normalised most easily by removing it altogether, alternatively it could be a sample of the same DemandRate as (A+B)/2 The longer C's duration, the greater its DemandRates effect on A and B's bit allocation, at 0 it ceases to have an effect.

The difference between doing the 2pass bitrate targeting on only A+B, and doing it on A+B+C where C is the clipped portion of the parent tracks is at least as transient to the test results, as the difference between the test samples used, and the tracks people will actualy encode guided by the tests results(!!)

I think you have incorrectly set "C:\Program Files\Windows Media Components\Encoder\WMCmd.vbs" as the encoder, not "CSCRIPT.EXE".

Thanks.

I had a wrong line there and I fixed it. Now it seems to start encoding, but I get this prompt when foobar sends the temp file to the encoder:"Microsoft ® Console Based Script Host has encountered a problem and needs to close. We are sorry for the inconvenience..."

I have installed about everything related with WM encoding, but nothing separately related with scripting. (Should I install something from e.g. here: MSDN / WIndows Scripting?)

Also, Windows Media Encoder itself (the GUI program) doesn't work anymore on this PC. It uses all available memory and crashes when trying to select a source file. I have tried all usual tricks e.g. uninstall/reinstall, search MS knowledgebase etc. It used to work about a year ago...

Only dbPowerAMP works.

Sorry about this being a bit OT, but it is related to a test contender and how people can use it.

Now my last attempt at waving the truth in front you guys:Suppose 3 phrases joined: A, B and C

[ .... ]

Ahem... it is SUPPOSED that 128+128+128/3 = 128 . That's not what we talked about. The target_bitrate for A,B,C, and Total are not necessarily equal, so you cannot simplify them like you did.

2-pass Encoding is doing an encode (generally with several tools disabled to speed it up) to get an estimated demandrate for each section of the sample. Depending on the deviation from the targetbitrate, the encoder increases or decreases the target quality, and starts the second encoding (this time, a real encode), probably an ABR one, but taking the previous results in consideration.

1-pass (usual ABR) does not have this "take information" step, It just starts encoding in fragments of a delimited time (like, saying, 2 seconds), and tries to constraint the demandrate to the targetbitrate.

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QUOTE (JohnV @ Nov 29 2005, 06:04 PM)

In short 10-20 sec hard samples our ABR may reach about 140kbps average because of the initial ABR buffer size. Full length tracks are equal or below 133kbps in almost all cases.

And an average Kbps of 140, would mean the first section was kicking in even higher than that (and towards the end, the reverse as the ABR algorithm tries balance it out). - Certainly quite a different bitrate distribution than the sample could recieve encoded insitu.

@Jaz - leave the condescension to those who know how to read a freekin' equation

@Jaz - leave the condescension to those who know how to read a freekin' equation

edit: more seplling and grammur

You put me in need to open my Oxford Dictionary... Yet, the the verb "condescend" means "to do something that one's rank, abilites etc do not require one to do". That, of course, in the context of your sentence is clueless.